12:47pm Wednesday 16 October 2019

Difficult to study risks of nanotechnology

Lars Samuelson

“The difficulty with this risk assessment is that we don’t know how much we don’t know. There are major gaps in our knowledge”, says Lund University ethics researcher Nils-Eric Sahlin. Genetic engineering has been labelled by many as shady corporate business, rightly or wrongly, and it would be unfortunate if the same thing happened to nanotechnology.

Nanoparticles are invisible to the naked eye and are almost unimaginably small. The size ratio between a nanoparticle and an orange is the same as between the orange and the globe. The mind boggles…

Such small particles can enter places which large particles cannot access. They can reach the innermost part of our lungs, they can pass through our mucous membranes and they may also be able to enter the brain via the blood. The possible effects of nanoparticles on our bodies and the environment are unknown. They are also very difficult to study. Normal, well-known substances actually behave differently at nano-level, where the normal laws of physics cease to apply. Instead it is laws of quantum physics which apply, giving nano-sized substances new optical, electrical and magnetic properties. Carbon in the form of carbon nanotubes becomes extra strong, gold and silver shine blue or red; metals can be converted into semiconductors or become insulating.

It is these new properties which provide the fantastic opportunities in nanotechnology.
So far it is mostly trivial products which are marketed under the ‘nano’ signature – things like shoe sprays, car paints and anti-wrinkle creams. But around the corner await more important applications such as homing nanoparticles which carry cancer drugs directly into the tumour cells, solar cells with thin films of nanocrystals, new catalytic convertors, cheaper and more energy-efficient nano-LEDs, and more.

“Therefore you cannot be just for or against nanotechnology. It offers enormous possibilities, but also applications that appear completely superfluous”, says Nils-Eric Sahlin.

This ‘on the one hand, on the other hand’ view characterises the entire issue of nanotechnology. On the one hand, we have actually been living for a long time with nano-products without knowing it. Both in 9th century Mesopotamia and during medieval times, clay goods were given a shiny surface using a coating of nanoparticles. There are a lot of nanoparticles in the air today, including from diesel emissions and the wearing down of car tyres, brake pads and train wheels. On the other hand, this is obviously not a reason to increase any risks that may exist by manufacturing and wearing down even more nano-related products.

The Engineering Nanoscience programme at the Faculty of Engineering (LTH) hardly entails any risks, as the students handle such small quantities of nanoparticles under controlled conditions.

“But of course we raise the issue. It’s important to give the students an awareness of the problem”, says programme director Knut Deppert.

In his view, suncreams and anti-wrinkle creams with nanoparticles are unnecessary and perhaps inappropriate, and calls them “a large-scale experiment with many participants”. However, in other products, such as electronics, the nanoparticles are enclosed so it is very unlikely that they could come out and cause harm.

Lars Samuelson is LU’s most internationally renowned nano-researcher, as well as being chief scientific officer for spin-off company QuNano, which manufactures energy-saving LEDs with nanotechnology. He sees nanoparticles from traffic as a clear health risk, and nano-creams as a conceivable risk.

“But in the past there was not the awareness there is today. Now major scientific conferences are being held on the possible risks of nanotechnology, and there is a political will to develop a system of regulation for the field”, he says.

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